Sterol and bile acid metabolism during development: 2. Identification of 3β-hydroxy-5-cholenoic acid (an intermediate in alternate pathway of bile acid synthesis) in newborn and fetal guinea pig

Steroids ◽  
1977 ◽  
Vol 30 (6) ◽  
pp. 815-825 ◽  
Author(s):  
Job R. Li ◽  
L. Marai ◽  
Dac M. Dinh ◽  
M.T. Ravi Subbiah
2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Thomas Q de Aguiar Vallim ◽  
Elizabeth J Tarling ◽  
Hannah Ahn ◽  
Lee R Hagey ◽  
Casey E Romanoski ◽  
...  

Elevated circulating cholesterol levels is a major risk factor for cardiovascular diseases (CVD), and therefore understanding pathways that affect cholesterol metabolism are important for potential treatment of CVD. The major route for cholesterol excretion is through its catabolism to bile acids. Specific bile acids are also potent signaling molecules that modulate metabolic pathways affecting lipid, glucose and bile acid homeostasis. Bile acids are synthesized from cholesterol in the liver, and the key enzymes involved in bile acid synthesis ( Cyp7a1 , Cyp8b1 ) are regulated transcriptionally by the nuclear receptor FXR. We have identified an FXR-regulated pathway upstream of a transcriptional repressor that controls multiple bile acid metabolism genes. We identify MafG as an FXR target gene and show that hepatic MAFG overexpression represses genes of the bile acid synthetic pathway, and modifies the biliary bile acid composition. In contrast, MafG loss-of-function studies cause de-repression of the bile acid genes with concordant changes in biliary bile acid levels. Finally, we identify functional MafG response elements in bile acid metabolism genes using ChIP-Seq analysis. Our studies identify a molecular mechanism for the complex feedback regulation of bile acid synthesis controlled by FXR. The identification of this pathway will likely have important implications in metabolic diseases.


Hepatology ◽  
1981 ◽  
Vol 1 (2) ◽  
pp. 146-150 ◽  
Author(s):  
Z. Reno Vlahcevic ◽  
Marc Goldman ◽  
Charles C. Schwartz ◽  
Jan Gustafsson ◽  
Leon Swell

Hepatology ◽  
2007 ◽  
Vol 2 (1) ◽  
pp. 59S-66S ◽  
Author(s):  
Marc Goldman ◽  
Z. Reno Vlahcevic ◽  
Charles C. Schwartz ◽  
Jan Gustafsson ◽  
Leon Swell

Animals ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 205
Author(s):  
Di Wu ◽  
Mingjuan Gu ◽  
Zhuying Wei ◽  
Chunling Bai ◽  
Guanghua Su ◽  
...  

Myostatin (MSTN) is a major negative regulator of skeletal muscle mass and causes a variety of metabolic changes. However, the effect of MSTN knockout on bile acid metabolism has rarely been reported. In this study, the physiological and biochemical alterations of serum in MSTN+/− and wild type (WT) cattle were investigated. There were no significant changes in liver and kidney biochemical indexes. However, compared with the WT cattle, lactate dehydrogenase, total bile acid (TBA), cholesterol, and high-density lipoprotein (HDL) in the MSTN+/− cattle were significantly increased, and glucose, low-density lipoprotein (LDL), and triglycerides (TG) were significantly decreased, indicating that MSTN knockout affected glucose and lipid metabolism and total bile acids content. Targeted metabolomic analysis of the bile acids and their derivatives was performed on serum samples and found that bile acids were significantly increased in the MSTN+/− cattle compared with the WT cattle. As the only bile acid synthesis organ in the body, we performed metabolomic analysis on the liver to study the effect of MSTN knockout on hepatic metabolism. Metabolic pathway enrichment analysis of differential metabolites showed significant enrichment of the primary bile acid biosynthesis and bile secretion pathway in the MSTN+/− cattle. Targeted metabolomics data further showed that MSTN knockout significantly increased bile acid content in the liver, which may have resulted from enhanced bile acid synthesis due to the expression of bile acid synthesis genes, cholesterol 7 alpha-hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1), and upregulation in the liver of the MSTN+/− cattle. These results indicate that MSTN knockout does not adversely affect bovine fitness but regulates bile acid metabolism via enhanced bile acid synthesis. This further suggests a role of MSTN in regulating metabolism.


Author(s):  
Frans Stellaard ◽  
Dieter Lütjohann

Regulation of bile acid metabolism is normally discussed as the regulation of bile acid synthesis, which serves to compensate for intestinal loss in order to maintain a constant pool size. After a meal, bile acids start cycling in the enterohepatic circulation. Farnesoid X receptor-dependent ileal and hepatic processes lead to negative feedback inhibition of bile acid synthesis. When the intestinal bile acid flux decreases, the inhibition of synthesis is released. The degree of inhibition of synthesis and the mechanism and degree of activation are still unknown. Moreover, in humans, a biphasic diurnal expression pattern of bile acid synthesis has been documented, indicating maximal synthesis around 3 pm and 9 pm. Quantitative data on the hourly synthesis schedule as compensation for intestinal loss are lacking. In this review, we describe the classical view on bile acid metabolism and present alternative concepts that are based on the overlooked feature that bile acids transit through the enterohepatic circulation very rapidly. A daily profile of the cycling and total bile acid pool sizes and potential controlled and uncontrolled mechanisms for synthesis are predicted. It remains to be elucidated by which mechanism clock genes interact with the Farnesoid X receptor-controlled regulation of bile acid synthesis. This mechanism could become an attractive target to enhance bile acid synthesis at night, when cholesterol synthesis is high, thus lowering serum LDL-cholesterol.


2014 ◽  
Vol 6 (247) ◽  
pp. 247ra100-247ra100 ◽  
Author(s):  
Jian Luo ◽  
Brian Ko ◽  
Michael Elliott ◽  
Mei Zhou ◽  
Darrin A. Lindhout ◽  
...  

Hepatic accumulation of bile acids is central to the pathogenesis of cholestatic liver diseases. Endocrine hormone fibroblast growth factor 19 (FGF19) may reduce hepatic bile acid levels through modulation of bile acid synthesis and prevent subsequent liver damage. However, FGF19 has also been implicated in hepatocellular carcinogenesis, and consequently, the potential risk from prolonged exposure to supraphysiological levels of the hormone represents a major hurdle for developing an FGF19-based therapy. We describe a nontumorigenic FGF19 variant, M70, which regulates bile acid metabolism and, through inhibition of bile acid synthesis and reduction of excess hepatic bile acid accumulation, protects mice from liver injury induced by either extrahepatic or intrahepatic cholestasis. Administration of M70 in healthy human volunteers potently reduces serum levels of 7α-hydroxy-4-cholesten-3-one, a surrogate marker for the hepatic activity of cholesterol 7α-hydroxylase (CYP7A1), the enzyme responsible for catalyzing the first and rate-limiting step in the classical bile acid synthetic pathway. This study provides direct evidence for the regulation of bile acid metabolism by FGF19 pathway in humans. On the basis of these results, the development of nontumorigenic FGF19 variants capable of modulating CYP7A1 expression represents an effective approach for the prevention and treatment of cholestatic liver diseases as well as potentially for other disorders associated with bile acid dysregulation.


2018 ◽  
Vol 237 (2) ◽  
pp. 139-152 ◽  
Author(s):  
Michelle M Chen ◽  
Clarence Hale ◽  
Shanaka Stanislaus ◽  
Jing Xu ◽  
Murielle M Véniant

Fibroblast growth factor 21 (FGF21) is a potent regulator of glucose and lipid homeostasis in vivo; its most closely related subfamily member, FGF19, is known to be a critical negative regulator of bile acid synthesis. To delineate whether FGF21 also plays a functional role in bile acid metabolism, we evaluated the effects of short- and long-term exposure to native FGF21 and long-acting FGF21 analogs on hepatic signal transduction, gene expression and enterohepatic bile acid levels in primary hepatocytes and in rodent and monkey models. FGF21 acutely induced ERK phosphorylation and inhibited Cyp7A1 mRNA expression in primary hepatocytes and in different rodent models, although less potently than recombinant human FGF19. Long-term administration of FGF21 in mice fed a standard chow diet resulted in a 50–60% decrease in bile acid levels in the liver and small intestines and consequently a 60% reduction of bile acid pool size. In parallel, colonic and fecal bile acid was decreased, whereas fecal cholesterol and fatty acid excretions were elevated. The long-acting FGF21 analog showed superiority to recombinant human FGF21 and FGF19 in decreasing bile acid levels with long duration of effect action in mice. Long-term administration of the long-acting FGF21 analogs in obese cynomolgus monkeys suppressed plasma total bile acid and 7α-hydroxy-4-cholesten-3-one levels, a biomarker for bile acid synthesis. Collectively, these data reveal a previously unidentified role of FGF21 in bile acid metabolism as a negative regulator of bile acid synthesis.


2021 ◽  
Vol 12 (2) ◽  
pp. 335-353
Author(s):  
Evette B. M. Hillman ◽  
Sjoerd Rijpkema ◽  
Danielle Carson ◽  
Ramesh P. Arasaradnam ◽  
Elizabeth M. H. Wellington ◽  
...  

Bile acid diarrhoea (BAD) is a widespread gastrointestinal disease that is often misdiagnosed as irritable bowel syndrome and is estimated to affect 1% of the United Kingdom (UK) population alone. BAD is associated with excessive bile acid synthesis secondary to a gastrointestinal or idiopathic disorder (also known as primary BAD). Current licensed treatment in the UK has undesirable effects and has been the same since BAD was first discovered in the 1960s. Bacteria are essential in transforming primary bile acids into secondary bile acids. The profile of an individual’s bile acid pool is central in bile acid homeostasis as bile acids regulate their own synthesis. Therefore, microbiome dysbiosis incurred through changes in diet, stress levels and the introduction of antibiotics may contribute to or be the cause of primary BAD. This literature review focuses on primary BAD, providing an overview of bile acid metabolism, the role of the human gut microbiome in BAD and the potential options for therapeutic intervention in primary BAD through manipulation of the microbiome.


2021 ◽  
Vol 22 (14) ◽  
pp. 7451
Author(s):  
Harpreet Kaur ◽  
Drew Seeger ◽  
Svetlana Golovko ◽  
Mikhail Golovko ◽  
Colin Kelly Combs

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive cognitive impairment. It is hypothesized to develop due to the dysfunction of two major proteins, amyloid-β (Aβ) and microtubule-associated protein, tau. Evidence supports the involvement of cholesterol changes in both the generation and deposition of Aβ. This study was performed to better understand the role of liver cholesterol and bile acid metabolism in the pathophysiology of AD. We used male and female wild-type control (C57BL/6J) mice to compare to two well-characterized amyloidosis models of AD, APP/PS1, and AppNL-G-F. Both conjugated and unconjugated primary and secondary bile acids were quantified using UPLC-MS/MS from livers of control and AD mice. We also measured cholesterol and its metabolites and identified changes in levels of proteins associated with bile acid synthesis and signaling. We observed sex differences in liver cholesterol levels accompanied by differences in levels of synthesis intermediates and conjugated and unconjugated liver primary bile acids in both APP/PS1 and AppNL-G-F mice when compared to controls. Our data revealed fundamental deficiencies in cholesterol metabolism and bile acid synthesis in the livers of two different AD mouse lines. These findings strengthen the involvement of liver metabolism in the pathophysiology of AD.


Lipids ◽  
1974 ◽  
Vol 9 (10) ◽  
pp. 731-737 ◽  
Author(s):  
Heleni Lansma ◽  
Rosemarie Ostwald

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